Diesel pump sprocket and timing Question

[citronut]

John
if you have cranked the engine over with the cam/crack timing out and you have bent valves, i very much doubt you will be able to rotate the engine once the timing has been rectified, as the bent valve/s will almost certainly foul the pistons even with the timing correct

[Sean602]

John, been reading your various threads about the various timing locations for the cam. The blanked off "alternate timing hole" in the head is an oil gallery drilling that's been plugged with the ball think this is what you have been getting confused over there is only the one threaded hole for the cam timing

[jgra1]

one hole for cam, two (can be used) for fuel pump if I remember correctly..
as Malcolm says, and Sean, there is the little block near the crankshaft pinion, which gets you in the right area for the flywheel hole for TDC

Good luck,
John
ps have you removed the rocker cover yet?

[John Plum]

I checked, finding i had crank pinned at the only discrete round hole I've found in about 5 + inspections, the crank pulley keyway points to centre of timing idler wheel - some way past the protrusion you mention as a marker.

So I cannot be sure I have TDC. I haven't found any other round hole - really there doesn't SEEM to be one where there 'should be'. I will just try to locate one there by feel with a pin.

As you say there is known to be another timing hole - perhaps the one I used.
Visually, a fancy oval slot appears around the point where key slot lines up with protrusion; could that lead into a timing pin hole?
The one I tried was the only plain round 7mm hole I could observe.

[jgra1]

i have a pic somewhere of the side of this engine, at TDC, will try and find it John..
its on a blog but I cant access from work..

[jgra1]

try here.. https://www.google.co.uk/search?hl=en&g ... B275%3B320" onclick="window.open(this.href);return false;

[John Plum]

Good News,

Back from holiday, thanks to your suggestions to find with certainty crank timing hole, using the pulley key slot and engine casing clues, I have found a round hole there which seems to give me proper timing; with timing belt on, camshaft now rotates nicely.

I'll put the rest back together now and try starting her up, hoping of course, there is no valve damage.
Cheers, John

[John Plum]

I spun her over, with all assembled, but would not fire up, not a bit - just spun round.

I could well be a tooth out with the timing belt, giving wrong oump timing, although I re-checked timing pin alignment after releasing the tensioner, and rotating the crank twice.
Because the pump timing hole, as machined into the engine casing is a little off, such that a bolt will not pin straight at any point.

I'll need to move it a tooth, having counted the teeth first between two points. But this is a little like guess work, trial and error.
I wondered, does anyone have a guide for timing by counting teeth, that is reliable?

In my case, I have counted 28 teeth between the central points of spokes on the two sprockets; ie two spokes to the left of the spoke with timing hole on cam sprocket, and one spoke to the left of timing hole spoke on fuel pump.
I figured on shifting my arrangement to 29 teeth.
Cheers John.

[KennyW]

John,

Don't know if this has been mentioned but the timing can be out by 180 degrees.

The cam and fuel pump sprocket turn twice to the crank once.

Kenny

[citronut]

u would not try playing guessing games, because if you havent done damage already toy could well trying yoyr suggestion,

just re/peg it all its the safest way , are you sure the had the correct tension applied before you rotated the engine by hand, after you peged everything off on the last attempt,

if its all pegged off correctly and correct tension applied, after you do the trial rotate by hand all the pegs should go straight back in, sometimes have to just rock the crank very slightly to get the flywheel peg in though

[John Plum]

Good point Ken. (I think u mean crank turns twice to each cam and pump revolution?).
Any easy way to confirm my position, or must I just try out rotating the crank once and refit cam belt?

[citronut]

the only/correct way to confirm were the crank is at in relationship to the cam and fuel pump is have it all pegged off,

as in John/jgra1's photo is the only visual way to see were the crank is situated,

with the crank sprocket woodruf key pointing upwards with its rear face in line with the front edge of the raised square block in the casting, this block is directly above the crank sprocket,

come on John keep your eye on the ball

[John Plum]

I didn't have my mind on this problem 100% at the start, due to panic with promises to my children for Easter, and the fact that my extensive experience had been with petrol engines, in the past, and reliance upon a Haynes manual.
But I have my eye on the ball since!

I have never been happy with the peg holes for the pump on this machine from the start.
I have just read a post concerning other xantias/XMs that they weren't always aligned at factory setting, and that the best way to refit was to count teeth. Here with me, it appears I could set the pump on one tooth further apart on the belt, with the 8mm bolt screwing down at a similar angle. The bolt will never go in straight, even with belt removed.

Actually, I don't see how the crank can be out by one turn, because the pump and cam are timed together revolving at tye same speed.

I have for sure set the crank as per keyway suggestion, having found the correct hole there (there are two holes).

So, crank, pump and cam have been set and , re-checked after fitting and tensioning belt, by both repegging and counting teeth. But pump appears to be out, set against a slightly offset peg hole.

I suppose I should now check under the cam cover - though on hand rotation valves appeared to operate.
Having said that, I am not happy with the pump timing. I hear with one tooth out, turbo diesels won't start.

[citronut]

so will either of the two pump sprocket locking pegs go in square, if so can you time it up with that,

how did this engine run before you started this belt change,

did you time it all up before dismantling from the start, if so did all the pegs go in at that point,

seems most odd as even though on occasion i have had to move the pump sprocket very slightly on pegging things off,

this has usually worked for me, i dont remember ever having one that the pump locking pegs would not go in,
on XUD engines at least,

Ken is right regarding the crank rotating twice for every one full turn of the cam,

but in your case as you have pegged the flywheel with the woodruf key as described above, and your cam is pegged off at about 4 oclock, this means your crank to cam timing is most definitely correct

[Sean602]

the engine doesnt care if its tdc at the top of what was exhaust stroke or compression stroke when you took the belt off as long as it IS at tdc and the cam is in the right place and the injector timing pegged it doesnt matter that the cam rotates at half crank speed.

have you touched the bottom pulley? thats the aux belt pulley rather than the lower timing belt pinion ? if you have it may be that the crank has moved in its keyway, the pulleys are also vernier fit on the shafts and so you can get some adjustment there but you have to peg it all up rather than guess/count teeth.